Aerial hookup for towing airplanes



Aug, 30, 1949. w. c. LAZARUS ETAL AERIAL HOOKUP FOR TOWING AIRPLANES 2 Shee'ts-Sheet 1 Filed Aug. 12, 1946 Aug 30, 1949. w. c. LAZARUS ETAL 2,480,145

AERIAL HOOKUP FOR TOWING AIRPLANES 2 Sheets-Sheet 2 Filed Aug. 12, 1946 Patented Aug. 30, 1949 HGOKUPFOR TGWING- AERPLANES WilliamlC. hazaruo orlandh, EmBober-t R. Paul,,

and James B, Hishel, Dayton,

lil-plplinatiulx Aiugnst- 12, 1948;. SerialNiL. 689,850 5 Claims- (01.241-3? Gra-nted undies the act amended mpcii 38, 1928s;

The invention described herein may be menu"- faotured and used by or forthe Government for governmental purposes without payment to us of any royalty thereon.

This invention relates to adevice by which a partially disabled airplane; i. e., one which still can. maintain itself aloft, can' be engaged and towed by a secondairplane;

Among the objects of this invention are the provision ofmeans that is safe, particularly during engagement. Qtlrer objects are to furnish a statically and dynamically stabilized positive hook on the end of a line extending from the damaged aircraft; also by means of two socks (drogues), to create a; vertical: or" nearly vertical section of trailing cable which at definite pick-up station. StilLanother obiectisto provide a positive connection into which the hook snaps upon contact, thereby making a link-chain connection rather than the needle threaded with knot typeof connection: common in the prior art.

Definite advantagesof this device are the absence of grapnels; the elimination of the necessity for intersecting two cables: i'n mid-air or for intersecting the. airplane. courses-t Positive advantages are the presence of both a weight and socks for stabilizing the trailed cable. Cables without weights whip uncontrollably and can cut a wing from another aircraft while those with only a weight and no socks cannot be safely approached by another aircraft.

In the drawings, Fig. 1 is a perspective view of the socks, the hook, the weight and a portion of the cable. Fig. 2 is a side elevation of the distressed airplane dangling the apparatus shown in Fig. 1 in position for the rescuing airplane to engage it.

Fig. 3 is a plan view of the towing airplane showing the mounting of the engaging device and hawser upon one wing thereof.

Fig. 4 is a side view showing the completed engagement, i. e., one plane towing the other.

Referring now to Fig. 1, I0 is a metal ball, preferably of brass and of about five inches diameter. A stem l l is provided with a pivoted eye I! which interlocks with a second pivoted eye l3 which is attached to the lower surface of the bend of a large hook it. The shank I5 of hook H is about twice as long as the bend it although such proportion is not critical. An eye I! is pivoted to the end of shank IS. The general proportions are therefore of a long-shanked fish-hook.

In the place where there would be a barb on an ordinary fish-hock, there is provided a snap I 8 pivoted at F9. A- lugl8a-, welded to shank l5; permits the snap to yield inwardly toward the bend, but' not to open outwardly. Also pivoted to' the hook at the-place where the barb of a fishhook would" be found, there is a windsock or dro'gue 29 attached by pivot 2+ by means of a plurality of rods 22 which terminate into the ringof thewihdsock 2131 To eyethere is attached acable ZTawhich may be of about diameter and about 1-8 feet long: The dimensions are not critical; To the end furthest fromthehook Hi there is a second snap hook or' openable' link 2-3 to which is attached a sock 2-4. The hook or link 23 engages an eye 25 of a nylon hawser 21-. The eye 2%- is protected by" a V-shapedlength of metal tubing 28. The hawser maybe about oneinch diameter and say 250 f 'eetlong.

The upper end of hawser 21 is attached by a conventionat tow release mechanism 29 to the belly of the distressed plane.

Referring now to Fig. 3; a cable 39 is attached by a conventional tow release mechanism 3+ to the'tailof' the fuselage. The cable passes under the elevator 32, to the wing tip 33" where it is retained by means of a bracket 34- which is safetywiredtothewing tip: It'is' also retained by being taped with adhesive tape to the wing surface. On the cables end there is a snatch hook 35 which has a guiding portion 36 which projects outward for about two feet at about 30 angle. Other angles or dimensions may be employed.

The snatch hook 35 is quite similar to hook I4 except that in place of a straight shank, it has a bent guiding portion 36 which makes an acute angle with the shank axis and is not equipped with pivots for a windsock. The angle at which the guiding portion assumes in relation to the plane wing is about 30 negative, 1. e., it points toward the tip of the fuselage or ahead of this point. In order to hold the hook to the wing tip, a permanently installed bracket 31 may be attached to the wing tip and the hook 35 taped to it by its shank.

The device is used as follows: The plane to be towed operated conventional tow release mechanism 29, thereby dropping weight it] and associated parts. Hawser 21 streams out behind the plane, but cable 21a assumes a nearly vertical position which is stabilized by the windsocks. The towing plane now approaches from behind and at a lower level than the plane to be towed and places the leading edge of whichever wing bears hook 35 in contact with cable 21a. Generally the left wing is preferred. The

airspeed of the towing plane should be M. P. H. faster than the towed plane. Consequently cable 21a bends over the leading edge, the upper windsock coming to rest usually on the top of the Wing. A gradual slippage or peeling toward the wing tip thenoccurs which may be aided by the pilot of the towing plane. Cable Tia-engages guiding portion 36 and forces open the latch of snap hook 35. As the towing plane begins to assume towing load, the tape holding hook 35 to the wing tip is torn loose. Hook 35 consequently falls and the slack in hawsers 21, 21a and 31] is taken up until the two hooks, 3 5 and M, are pulled into engagement. Full towing load is then assumed, the stretch of nylon hawsers 21, taking up a considerable amount of the shock.

At the start of the maneuver, the towing plane should be about 100 feet below the one to be towed, but as the connection is made it may rise slightly. The towed plane is preferably higher than the towing one thruout the course to the base.

cable is caught and held by said receiving snap hook, a tow connection will be established between the airplanes,

2. In combination, a long elastic hawser, a substantial length of cable attached to one end thereof, a snap hook attached to the free end of said cable, a weight revolubly attached to said catch and hold said weighted I easily rupturable an airborne Wing tip belonging to the same airinto engagement with said hook, said hook being attached to the free end of said hawser and an means attaching said hook to craft. as the said anchorage.

4. A snap hook which comprises a shank, a pivoted eye on the extremity of said shank, a bend, a pivoted eye mounted at the bottom outer portion substantially at the outer end thereof.

5. A snap hook comprising a shank, a bend, a

bent over portion, a snap between said bent over portion and shank and a hawser guiding poracute angle outwardly with the longitudinal axis WILLIAM C. LAZARUS. ROBERT H. PAUL. JAMES B. RISHEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 7 Name Date 40 1,848,372 Moran Mar. 8, 1932 1,925,555 Bradshaw Sept. 5, 1933 2,166,575 Atcherley July 18, 1939 2,261,598 Tyson Nov. 4, 1941 2,388,013 Rasor Oct. 30, 1945 2,396,071 Anderson et al. Mar. 5, 1946 2,418,702 DuPont Apr. 8, 1947 

